Patent · US Expired

Capacitance sensitive switch and switch array

US5508700A · kind A · utility

51Cited by
20References
64Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 17, 1994
Grant dateApr 16, 1996
Priority date
Expiry dateMar 17, 2014

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K2217/960715
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A capacitance-sensitive switch unit including a capacitive element operable to produce an effective capacitance dependent upon the physical proximity of objects relative thereto, a first selector signal input connected to the capacitive element to enable a first input signal to charge the effective capacitance, a threshold signal producing circuit connected to the capacitive element, for producing a threshold signal which is rendered active when the effective capacitance charges to a pre-defined potential, a switching circuit for selectively connecting the capacitive element to the threshold signal producing circuit in response to a switching signal and a discharge control circuit connected to the capacitive element, for selectively discharging the effective capacitance independently of the input signal, in response to a discharge signal. Also disclosed is a switch array employing structure similar to the above.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.